In an interview Monday night on Fox News with Laura Ingraham, Kelly complimented Gen. Robert E. Lee, who led the South's military in open rebellion against the U.S. government when angry Southern landowners got concerned they might not be able to own human beings anymore.

"Look, all of our leaders have flaws. That doesn't diminish the contributions to our country and certainly can't erase them from history," Sanders said Tuesday. "And General Kelly was simply making the point because history isn't perfect doesn't mean it's not our history."

Kelly, speaking out over the removal of Civil War monuments, called slave-owning Confederate General Robert E. Lee "an honorable man" and said the war was sparked by "the lack of the ability to compromise."

The retired Marine Corps general was responding to a question about a Virginia church's decision to remove historical markers for Lee and George Washington.

“There are a lot of historians that think that. And there are a lot of different versions of those compromises,” Huckabee Sanders said. (NICHOLAS KAMM/AFP/Getty Images)

The Episcopal church in Alexandria, Va., that was once attended by Lee and Washington decided Thursday to remove two plaques dedicated to the former parishioners, believing the set was an "obstacle to our identity as a welcoming church."

Congressional Black Caucus Chair Rep. Cedric Richmond, D-La., criticized Kelly, saying he "needs a history lesson" for minimizing the role of slavery in bringing about the Civil War.

"The Civil War was not a disagreement between 'men and women of good faith on both sides.' It was a struggle for the soul of this country," Richmond said. "Thankfully, the right side won the war and slavery is no longer the law of the land."

Kelly foe Frederica Wilson, the Florida congresswoman he insulted after she complained about President Trump's tone-deaf condolence call to the family of a fallen soldier, wrote, "What exactly, I wonder, would be the right 'compromise' between slavery and freedom for human beings?"

Kelly, speaking out over the removal of Civil War monuments, called Confederate General Robert E. Lee “an honorable man” and said the war was sparked by “the lack of the ability to compromise.” (Fox News)

Several historians countered Kelly and the White House's claims.

"This is profound ignorance, that's what one has to say first, at least of pretty basic things about the American historical narrative," David Blight, a history professor at Yale University and author of "Race and Reunion: The Civil War in American Memory," told the Washington Post. "I mean, it's one thing to hear it from Trump, who, let's be honest, just really doesn't know any history and has demonstrated it over and over and over. But General Kelly has a long history in the American military."

Stephanie McCurry, a history professor at Columbia University and author of "Confederate Reckoning: Politics and Power in the Civil War South" agreed.

"The reason there was no compromise possible was that people in the country could not agree over the wisdom of the continued and expanding enslavement of millions of African-Americans," she said.